Hammer head having an antislip and wear-resistant striking face surface

ABSTRACT

A forged steel hammer head including an impact head proper having a striking face on one end thereof is provided with a layer of tungsten carbide electrodeposited on the end, forming an outer surface on the striking face and penetrating the impact head proper, thereby providing an antislip and wear-resistant surface on the striking face.

. w. r mm States atet H 1 9 Porter Feb. fi, 11972 [54] HAMMER HEADHAVENG AN ANTISLIP [56] References Cited AND WEAR-RESISTANT STRIKING FACSURFAE UNITED STATES PATENTS ml Pom-r, Hem 5338'53 351323Z3135???:JJJJ::JJ::JJJJJJJJJJJJJJJ:@1233? 3 [73] Assignee: Vaughan &Bushnell Mfg. (30., l-lebron, Ill.

Primary Examiner-Andrew R. Juhasz Flled: 13, 1969 AssistantExaminerMichael Koczo, Jr. [21] AppL No: 876,300 Attorney-Norman H.Gerlach [57] ABSTRACT [52] 11.8. Cl ..145/29 R, 76/DIG. 11 A forgedSteel hammer head including an impact head propel, having a face on oneend thereof is provided a [58] Field 01: Search 145/29; 76/DIG. 1 115 g2130; layer oftungsten carbide electrodeposited on the and, forming anouter surface on the striking face and penetrating the impact headproper, thereby providing an antislip and wear-resistant surface on thestriking face.

1 Claims, 4 Drawing Figures PATENIED FEB 8872 131 49 324 FIG] INVENTORLAURENCE W. PORTER ATTORNEY HAMMER HEAD HAVING AN ANTISLIP AND WEAR--RESISTANT STRIKING FACE SURFACE This invention relates to portableimpact tools and has particular reference to a hammer construction.

It has long been considered desirable to provide on the forged steelhead of a hammer a striking or impact surface which will reduce orminimize the tendency for the hammer head to slip or skid off of thehead of a nail or other fastener when struck with the hammer, andthereby minimize nail bending. For this purpose, hammer heads used fordriving nails and the like, such as employed in carpenters hammers, areconventionally provided with a milled or scored striking face. However,the milled face heads are in general limited to use in rough work, forexample, structural framing and assembly of forms. The milled face headsare generally unsuitable for finishing work inasmuch as the milledstriking surface mars the surface of the wood or other material intowhich the nails are driven. Consequently, it is necessary to use twohammers, employing a hammer with a milled face head where suitable toobtain the advantages of an antislip surface, and changing to a hammerwith a smooth face head to preserve the surface of the wood or othermaterial in finishing work. It would be a great advantage to be able toemploy the same hammer for both rough and finishing work whileminimizing hammer head slippage on the nail head during both types ofwork and preserving the finish of the work surface in the latterinstance.

The milled face hammer heads also have the disadvantages that they wearmore rapidly and are damaged more readily, inasmuch as the area of thestriking surface is markedly reduced owing to the removal of metal bymilling and also because the striking surface constitutes a series ofsmall protrusions rather than a continuous smooth solid surface.Consequently, their performance level falls more rapidly and the hammersmust be replaced more frequently than hammers having smooth face heads.

It is an object of the present invention to provide a forged steelhammer head, and a hammer embodying the same, having an antislip andwear-resistant striking face surface which satisfies the need for anantislip hammer head suitable for both rough and finishing work andwhich also has high wearability and durability.

A particular object is to provide a hammer head having a striking facesurface that has antislip characteristics while not marring the surfaceof the work upon impact.

Another particular object is to provide a hammer head having suchstriking face surface that also eliminates the wear and durabilityproblems of milled face heads and further provides increased wearresistance over smooth face heads.

A specific object is to provide in a forged steel hammer head includingan impact head proper having a striking face on one end thereof, a layerof tungsten carbide electrodeposited on the end forming an outer surfaceon the striking face and penetrating the impact head proper, therebyproviding an antislip and wear-resistant surface on the striking face.

An additional object is to provide a hammer head accomplishing theforegoing objects which is readily and economically constructed,requiring but a very simple operation on an otherwise finished tool.

These and other objects, advantages and functions of the invcntion willbe apparent on reference to specification and to the accompanyingdrawings, in which like parts are identified by like reference symbolsin each of the views, and in which:

FIG. I is a perspective view of a carpenters claw hammer provided with ahead having an antislip and wear-resistant striking face surface inaccordance with the invention;

FIG. 2 is an enlarged elevational view of the striking face surface onthe hammer head shown in FIG. 1;

FIG. 3 is an enlarged view partly in cross section and partly in sideelevation of a portion of the impact head proper of the hammer headshown in FIG. 1; and

FIG. 4 is a view like FIG. 2 illustrating another embodiment of theinvention.

Referring to the drawings, particularly FIG. I, a carpenter's straightclaw or ripping hammer 10 is illustrated, and it includes a woodenhandle 12 and a forged steel hammer head 14 constructed in accordancewith the invention. The invention is equally applicable to various otherstyles and types of portable or manual hammers and the heads thereof,employed for driv ing nails or other fastening means, including curvedclaw or nail hammers, claw hammers having welded steel or tubular steelhandles, and hammers designed to accomplish other functions while havinga striking face on the hammer head employed to a greater or lesserextent for driving nails or other fastening means, or for striking othersurfaces or objects where antislip or wear resistance properties aredesirable.

The illustrative hammer head 14 is of the bell-faced type, and itincludes a medial body portion or region 16 and, projecting outwardlyfrom opposite ends thereof, an impact head proper l8 and a claw portionor region 20. The impact head proper 18 is integrally joined to themedial body portion 16 by a constricted portion 22 of polygonal crosssection. The medial body portion 16 is provided with a generallyrectangular socket or opening 24 extending transversely therethrough.The socket 24 receives a distal connecting section 26 of the handle 12therein, where the handle is secured in place by wedges, not shown. Thehandle also includes a proximal grip section 30, by which the hammer 10is held during use.

The impact head proper l8 constitutes a substantially cylindricalportion of the hammer head 14, and it terminates at its outer impact end28 in a circular, slightly convex striking face 32. Alternatively, thestriking face 32 may be flat. A peripheral bevel edge or face 34 aroundthe periphery of the striking face 32 serves to minimize chipping. Theclaw portion 20 is integral with the medial body portion 16, and isbifurcated at 36 to provide a pair of divergent claws 38 of conventionalstructure.

The hammer head 14 is constructed of forged steel, suitably heated,annealed, ground, hardened and finished, to provide the proper degreesof hardness and toughness in respective portions thereof. Theillustrative and other suitable hammer heads may be constructed of thevarious steels conventionally employed therein, including, for example,high carbon steel (e.g., about 0.8 percent carbon as in AISI No. 1,078or 1,080 steel) and alloy steels such as chromium-vanadium alloy steels(e.g., AISI No. 6150). A claw hammer, such as illustrated, isheat-treated to provide a Rockwell C hardness of 50-60 on the strikingface 32, and 40-55 on the claws 38.

The hammer head 14 includes a layer or coat 40 of tungsten carbideelectrodeposited on the outer impact end 28 of the head proper 18. Thetungsten carbide layer 40 forms an outer surface 44 on the striking face32, and the layer also penetrates the head proper 18, as illustrated inFIG. 3. Electrodeposition causes molecular tungsten carbide to penetratethe striking face 32, forming deposits within the head proper 18. Also,carbide deposits build up on the surface of the striking face 32,thereby forming the outer surface 44 thereon. In the preferred practiceof the invention, the layer 40 formed by such carbide depositspenetrates the head proper 18 for about one-half of the layer depth. Itis also preferred that the depth or thickness of the layer 40 be on theorder of 0.004 inch, with the layer extending into the head proper 18for about 0.002 inch.

FIG. 4 illustrates another embodiment of the invention, wherein atungsten carbide layer 46 like the layer 40 is electrodeposited on thebevel edge portion of the outer impact end 28, in the same manner. Thelayer 46 forms an outer surface 48 on the bevel edge 34, and the layeralso penetrates the head proper 18. The characteristics of the layer 46,including penetration and depth, are the same as described above for thelayer 40 on the striking face 32 portion of the outer impact end 28.

The tungsten carbide layers 40 and 46 are applied in a very simple,convenient and rapid manner employing conventional equipment forelectrodeposition of the carbide, which is commercially available. Thelayers are applied by means of a spark discharge from a tungsten carbideelectrode subjected to an electrical potential, in a hand-heldelectromagnetic vibratory electrical tool, which interrupts the currentat a regular frequency, e.g., 120 pulses per minute. The electrode isplaced against or closely adjacent to the surface of the striking face32 or the bevel edge 34, and tungsten carbide is discharged from theelectrode and deposited beneath and on the adjacent surface, in a depthor thickness depending upon the spark gap and the potential. Theelectrode is moved over the surface of the striking face 32 or of thebevel edge 34, to form the layer 40 or 46 thereover. The tungstencarbide is fused into the head proper l8 and deposited thereon withoutoverheating the surfaces thereof and affecting their properties.

Available equipment includes Model 312 Rocklinizer (RocklinManufacturing Co), which is employed at its maximum dial setting toprovide a tungsten carbide layer 40 or 46 of about 0.004 inch depth. Itis preferred to provide such layer depth corresponding to the capacityof the particular equipment, although lesser depths may be providedwhile yet achieving improved results in accordance with the invention.Greater layer depths may be provided but do not appear to be needed.Another brand of available equipment is identified as Carbumatic(Mercuria Company, Inc.). The commercial equipment was previouslyemployed for coating machine tools and dies.

The outer tungsten carbide surface 44 on the striking face 32 has verydesirable antislip characteristics, apparently due to the presence ofhard tungsten carbide deposits forming a roughened or pitted surfacetending to prevent relative movement between the hammer head and thenail head. While being rough relative to a smooth surface striking face,the outer surface 44 is relatively even as compared to a milled face, sothat the surface of the work is not marred. The antislip and finishretaining characteristics of the hammer 10 were demonstrated inconstruction work, where the carpenters found that they could work downnails without slip or skidding off of the nail heads, and in addition,they could change from rough framing to finishing work using the samehammer without marring the wood, which was a marked advantage.

The outer tungsten carbide surface 44, being formed by hard, closelyadjacent carbide deposits, also is very wear-resistant and durable, incontrast to the reduced wearability and durability ofa milled face.Further, the carbide surface 44 has enhanced wear resistance as comparedto an uncoated striking face 32, especially desirable for work underabrasive conditions, as in concrete work. The invention thus providesthe multiple functions of minimizing slip, preserving the finish of thework surface, and increasing wear resistance.

The outer surface 48 of the tungsten carbide layer 46 on the bevel edge34 likewise is very wear-resistant and durable. In the absence of thelayer 46, the bevel edge tends to round off, into the striking face 32,which reduces the area of the striking face. The additional wearresistance imparted by the layer 46 is also especially desirable forwork under abrasive conditions.

The invention thus provides a hammer head having a most advantageousantislip and wear-resistant striking surface, which can be used moreefficiently where hammer head slip is a factor, as in driving nails orother fastening means, is a dual purpose tool suitable for both roughand fine work, and is very serviceable and long-lasting. While preferredembodiments of the invention have been described and illustrated, itwill be ap parent to those skilled in the art that various changes andmodifications may be made within the spirit and scope of the invention.It is intended that such changes and modifications be included withinthe scope of the appended claims.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. In a forged steel claw hammer head including a medial body portion, aclaw portion integral with said body portion and projecting outwardlyfrom one end thereof, and an impact head proper integral with said bodyportion and projecting outwardly from the opposite end thereof, saidimpact head proper having a striking face on its outer end, saidstriking face having a minimum Rockwell C hardness of about 50, a layerof tungsten carbide having a depth on the order of 0.004

inch electrodeposited on said outer end forming an outer sur face onsaid striking face and penetrating said impact head proper for aboutone-half of the layer depth, said layer being deposited by a sparkdischarge from tungsten carbide electrode to preserve the striking faceproperties, thereby providing an antislip and wear-resistant surface onsaid striking face.

1. In a forged steel claw hammer head including a medial body portion, aclaw portion integral with said body portion and projecting outwardlyfrom one end thereof, and an impact head proper integral with said bodyportion and projecting outwardly from the opposite end thereof, saidimpact head proper having a striking face on its outer end, saidstriking face having a minimum Rockwell C hardness of about 50, a layerof tungsten carbide having a depth on the order of 0.004 inchelectrodeposited on said outer end forming an outer surface on saidstriking face and penetrating said impact head proper for about one-halfof the layer depth, said layer being deposited by a spark discharge fromtungsten carbide electrode to preserve the striking face properties,thereby providing an antislip and wearresistant surface on said strikingface.